Background: Side-specific test procedures are mandatory in order to assess the function of peripheral vestibular receptors. Semicircular canals (SCC) and vestibulo-ocular reflex (VOR) can be tested by the Halmagyi and Curthoy head impulse test (HIT) and recently by means of the video head impulse test (vHIT). The vHIT procedure is a new method to measure eye and head velocity during brief and rapid head impulses. This method provides objective information of VOR and detects both overt and covert catch-up saccades.
Materials and methods: As clinical experiences with vHIT are limited, in this study the horizontal VOR (hVOR) was examined by means of the vHIT in 142 consecutive patients with acute or chronic vestibular syndrome.
Results: A total of 20 healthy volunteers served as a control group and exhibited a normal average VOR gain of 0.97 ± 0.09 without re-fixation saccades. In patients, 47.6% showed a pathological vHIT whereas 52.4% revealed a normal test result. Covert catch-up saccades could be revealed in 13.7% by means of vHIT whereas in 86.3% overt catch-up saccades alone or in combination with covert catch-up saccades were found in the majority of catch-up saccades in peripheral vestibular disorders.
Conclusions: By means of the vHIT it is possible to obtain a side-specific and quantitative assessment of hVOR. Video-head impulse test is a reliable tool for vestibular testing even in bedside examinations of patients suffering from dizziness.